RU2516445C2 - Electromagnetic unit of electromagnetic valve - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to electrical engineering and electromagnetic units, primarily for the electromagnetic drive of a fuel injector. The electromagnetic unit (2) has a housing component (20) with a coil (30) inserted therein. An armature (36) is placed on the first side (31) of the coil (30). A cover (21), which closes the housing component (20) and is joined with said component by a weld joint (22), is located on the second side (34) of the coil facing the first side (31) of the coil.

EFFECT: facilitating matching of a socket (28) on a connection pipe (24) connected to the housing component (20) or integrated with the housing component, with specific requirements.

15 cl, 3 dwg

Description

State of the art

The present invention relates to an electromagnetic assembly of an electromagnetic valve, especially for an electromagnetic drive of a fuel injector. The invention relates primarily to fuel nozzles for fuel systems of diesel engines.

A fuel nozzle for an internal combustion engine (ICE) is known from EP 1612400 A1. Such a known fuel injector has an electromagnetic drive that controls the flow of fuel through a drain throttle. In this way, indirect control of the operation of the fuel nozzle for fuel injection can be carried out. The electromagnetic assembly of the electromagnetic drive is located in body parts screwed to each other. In this case, the most important elements of the electromagnetic unit are enclosed in plastic, respectively, a plastic shell. Plastic electrically isolates the elements of the electromagnetic assembly relative to the metal housing of the fuel injector. In addition, o-rings are located at various places in the plastic shell.

A disadvantage of the fuel injector known from EP 1612400 A1 is the relatively high complexity and cost of its manufacture. Another disadvantage of such a known fuel injector is that the connection point of the drain fuel pipe has a complex design and that it is impossible or possible only under high costs to coordinate with the design features of various systems.

Summary of the invention

An advantage of the electromagnetic assembly proposed in the invention, as claimed in claim 1, and the fuel injector proposed in the invention, as claimed in claim 16, consists in simplifying their manufacture and, above all, in the possibility of their relatively simple coordination with the design features of various systems. In this case, first of all, a relatively simple matching of the connector (its size and / or shape) for connecting the drain fuel line is possible.

Various preferred embodiments of the electromagnetic unit claimed in claim 1 and the fuel injector claimed in claim 16 are presented in the respective dependent claims.

In one such preferred embodiment, the lid is connected to the body part by a welded joint. For this, it is preferable to use the laser welding method. It is further preferred that the welded joint forms a welded joint between the lid and the body part. In this way, it is possible to obtain not only durable due to the ability to withstand workloads, but also hermetically separating the inner space of the body part from the outer space of the weld. The weld can be positioned either radially or axially.

According to the invention, a pre-compressed elastic element is located between the second side of the coil and the inner side of the lid, which loads or compresses the coil by the force of its pre-compression, which, with its first side, rests on the ledge of the housing part. In this way, the coil is fixedly fixed in the body part. In this regard, a variant is further preferred in which an anchor rod is connected to the anchor, which at least partially passes through the central hole of the coil, and a stop for the anchor rod is provided on the elastic element, restricting its movement when the anchor moves to the first side of the coil. This option provides great opportunities for the design of the cover. In this case, first of all, it is also possible to connect the nozzle to the cap by fusion.

In this case, it is preferable to further perform an elastic element with a central bulge facing the Central hole of the coil and forming a stop for the anchor rod. This option provides the ability to easily adjust the position of the stop, limiting the course of the anchor rod. In addition, in order to be able to drain the fuel or to perform another similar function in the lid, a drainage hole oriented (approximately) in the axial direction can be made, thanks to which the anchor rod or the elastic element does not impede the drainage or removal of fuel from the inner space of the body part.

In another preferred embodiment, the anchor rod connected to the anchor passes through the central hole of the coil, the inner side of the cover facing the second side of which limits the stroke of the anchor rod when moving the anchor to the first side of the coil. In this case, the support for the anchor rod forms the inner side of the cover. In this case, by adjusting the position of the cover in the housing part during assembly, it is primarily possible to precisely set the stop position restricting the travel of the anchor rod, and thereby the anchor.

In this regard, it is preferable to make the elastic element in the form of a disk-shaped elastic element, which has a central hole through which the anchor rod can be passed. Due to this, the possibility of a simple design of the elastic element, pressing the coil by the force of its preliminary compression, is provided.

In a further preferred embodiment, the cap has at least one opening through which an electrical contact part passes to the coil and which is sealed by an o-ring located therein. Moreover, in the hole, in addition, you can provide a support ring, which is preferably located closer to the inner side of the cover flush with this side to ensure, for example, the presence of support for the elastic element in the area of the hole in the cover and some protection inserted into the sealing ring .

In a further preferred embodiment, in order to be able to divert fuel from the inner space of the body part to the fuel tank or a similar tank, a nozzle is provided located on the outside of the cap, which has at least one drain hole connecting the enclosed space of the body part of the housing in which the coil is located, with a drain channel in the nozzle. In this case, it is preferable to further make a drain hole in the lid with a countersink recess through which the drain hole enters the interior of the housing part. Due to the presence of such a countersink recess, a reliable fuel drain through the drain hole is provided and the manufacture of a cover is simplified.

The nozzle is preferably connected to the cap by a welded joint. In this case, the weld, which is preferably performed by the method of laser welding, has durability due to the ability to withstand working loads and hermetically separates the drain channel in the pipe from the outside.

In another embodiment, the nozzle can also be integral with the cap.

Preferably, at least one radially outer annular groove is further provided on the nozzle. Such an annular groove in combination with extruded plastic lining prevents the penetration of water, moisture or other liquids to the weld. The annular groove can primarily be made in the form of a kind of water-retaining groove. In this way, it is possible to protect one or more welds, primarily connecting the pipe to the weld lid, from corrosion.

In another preferred embodiment, the cover is made disk-shaped. Such a design of the cover facilitates its precision mounting on the body part. In addition, a certain fit of the elastic element to the inner side of the lid is provided. In addition, the manufacture of an electromagnetic unit is cheaper, while it is possible to coordinate it with various requirements. So, for example, the shape and / or dimensions of the nozzle can be practically arbitrarily varied to match it with various connectors for connecting the drain fuel line leading to the fuel tank. In this case, no other coordination or at least no coordination of the body part is required, due to which the electromagnetic assembly remains practically unchanged, especially with regard to its built-in parts, such as, for example, an anchor and a coil.

Brief Description of the Drawings

Below the invention is described in more detail by the example of some preferred variants of its implementation with reference to the accompanying drawings, in which the same elements are denoted by the same positions and in which, in particular, is shown:

figure 1 is a schematic fragmentary view in section of a fuel injector with an electromagnetic unit in accordance with the first embodiment of the invention,

figure 2 is a view depicted in figure 1 of the electromagnetic unit in section by plane II-II in accordance with a second embodiment of the invention,

figure 3 is a similar to that shown in figure 2 view of the electromagnetic node in accordance with a third embodiment of the invention,

in Fig.4 - depicted in Fig.1 a cover with an elastic element of an electromagnetic unit in accordance with a fourth embodiment of the invention and

5 is an enlarged view of the fragment V of the electromagnetic assembly indicated in FIG. 3 in accordance with a fifth embodiment of the invention.

Description of Embodiments

Figure 1 schematically and fragmentarily in section shows a fuel nozzle 1 with an electromagnetic unit 2 in accordance with the first embodiment of the invention. Such a fuel injector 1 can be used primarily as a fuel injector or fuel injector in fuel systems of diesel engines. It is particularly preferable to use a similar fuel injector 1 in fuel systems with a common high-pressure fuel line (also called a high-pressure fuel cell or "common rail"), from which diesel fuel is supplied under high pressure to several fuel nozzles 1. The electromagnetic assembly 2 according to the invention most suitable for use in such a fuel injector 1. In this case, the electromagnetic assembly 2 can serve as part of the electromagnetic valve 3, which serves as an electric ferromagnetic drive the fuel injector 1 to control it. At the same time, the fuel injector 1 proposed in the invention and the electromagnetic assembly 2 proposed in the invention are also suitable for use in other systems.

The fuel nozzle 1 has a nozzle 4 with a needle 5 located in it. In this case, the fuel pressure in the control cavity 6 acts on the needle 5. In addition, the fuel pressure in the fuel cavity 7 also acts on the needle 5. High-pressure fuel is supplied to the fuel cavity 7 through the fuel channel 9 by a high pressure pump, primarily from a common high pressure fuel line. At the same time, an inlet choke 10 branches off from the fuel channel 9, leading to the control cavity 6. A drain choke 11 is led from the control cavity 6, and the solenoid valve 3 controls the flow of fuel through which from the control cavity 6. The solenoid valve 3 is made in the form of a conical valve (conical valve). When the electromagnetic valve 3 is activated, the control seat 12 is released to open the drain throttle 11, as a result of which the pressure in the control cavity 6 drops. As a result, the needle 5 begins to act seeking to open its hydraulic force. Under the action of this force, the needle 5 rises from the contact surface 13 of its seat, as a result of which the sealed seat formed between the needle 5 and the contact surface 13 opens, and the fuel, passing through the open sealed seat from the fuel chamber 7, is sprayed through the spray hole 14.

The electromagnetic assembly 2 has a body part 20. A cover 21 is inserted into this body part 20. The cover 21 is connected to the body part 20 by a circular weld. Such a weld 22 is made in the form of an axial weld. The welded seam 22 ensures the tightness of the inner space 23 of the housing part 20. The electromagnetic assembly 2 also has a nozzle 24. In the considered embodiment, the nozzle 24 is integral with the cover 21. The nozzle 24 forms a drain channel 25. The inner space 23 of the housing part communicates with the drain channel 25 in the pipe 24 through the drain holes 26, 27 made in the cover 21. Thus, the fuel can be removed from the inner space 23 of the body part through the drain channel 25 in the pipe 24 back to the fuel tank or the like capacity.

A connector 28 is provided for connecting the drain fuel pipe to the pipe 24. The connector 28 can be relatively simple to coordinate with the specific design features of the drain fuel pipe connected to it without the need for structural changes to other components of the electromagnetic assembly 2.

In the interior space 23 of the housing part 20, there is a coil 30 inserted into it, which in mounted state is supported by its first side 31 on the step 32 of the housing part 20. When assembling, the coil 30 is inserted into the housing part 20 through its opening and then closed with a lid 21 .

The electromagnetic assembly 2 has a disk-shaped elastic element 33 located in the inner space 23 of the body part 20. Such an elastic element 33 is supported on the one hand on the second side 34 of the coil 30, and on the other hand, on the inner side 35 of the cover 21. In the present embodiment the elastic element 33 rests on the inner side 35 of the cover 21 in its central part between the drain holes 26, 27. This allows the flow of fuel through the drain holes 26, 27.

The elastic element 33 is mounted with pre-compression, which is provided when the cover 21 is placed in the body part 20. The elastic element 33 with the force of its pre-compression loads the coil 30 and in this way fixes it fixedly in the body part 20.

The electromagnetic assembly 2 further has an anchor 36 which interacts with the coil 30. In addition, an anchor rod 37 is connected to the anchor 36. The anchor rod 37 passes through the coil 30. The elastic element 33 also has a central opening 38. In this central hole 38, sleeve 39 is installed. An anchor rod 37 is inserted into this sleeve 39. When the electromagnetic valve 3 is activated, i.e. when applying electric current to the coil 30, the anchor rod 37 can move in the hole 38 in the elastic element 3 against the stop on the inner side 35 of the cover, while with this movement of the anchor rod along with it toward the coil 30, the anchor 36 also moves. 37, and thereby the anchor 36 is limited by the stop of the anchor rod 37 in the inner side 35 of the cover. In addition, a spring 40 is provided, which on the one hand rests on the armature 36, and on the other hand draws the sleeve 39 to the inner side 35 of the cover 21.

The coil 30 is equipped with a casting composition that protects its electrical components from contact with fuel or other liquids present in the interior space 23 of the body part 20.

In addition, figure 1 shows the electrical connection (electrical contact terminal) 41 with wiring 42, which provide the ability to supply electric current to the coil 30 to operate the solenoid valve 3, which is also described in more detail below with reference to figure 2.

The housing part 20, facing away from the first side 31 of the coil 30 of its second side 34, is closed by a cover 21, which is inseparably connected to the housing part 20 by welding along the weld 22. Such a design makes it easy to mount the coil 30 by placing it in the housing part 20. In addition the housing part 20 has a step 43, which allows you to accurately position the cover 21 when it is placed in the housing part 20. Due to this, the inner side 35 of the cover 21 is located at a strictly defined distance from the first side 31 coils. In addition, the inner side 35 of the cover 21 provides a strictly defined restriction of the stroke of the armature 36 with the anchor rod 37 relative to the control seat 12.

In Fig. 2, a section through the plane II-II shows an enlarged fragment of the electromagnetic assembly 2 shown in Fig. 1 of the fuel nozzle 1 shown in Fig. 1 in accordance with a second embodiment of the invention. In this embodiment, the cover 21 is connected to the body part 20 by a radial weld 22. In addition, the pipe 24 is made in the form of a part separate from the cover 21. In this case, the pipe 24 is connected to the cover 21 by a radial weld 22 '. The weld seam 22 'is made corresponding to the weld seam 22. The pipe 24 is located on the outer side 44 of the cover 21 and is welded inseparably to it on this outer side 44. To simplify the drawing, it does not show the anchor 36 connected to the anchor rod 37, but also a spring 40 and a sleeve 39. The coil 30 has a central hole 45 through which the anchor rod 37 is passed.

Openings 46, 47 are provided in the cover 21, through which electrical contact parts (contact leads) 48, 49 are passed. Each of these electrical contact parts 48, 49 is connected to one end of the coil winding 30, so that outside the housing part 20, electrical connections are made between the coil 30 and the current source through the wiring 42 and the electrical connection 41. O-rings 50, 51 are located in the openings 46, 47, which serve to seal the inner space 23 of the housing part relative to the surrounding rostranstva. In addition, support rings 52, 53 are provided in the openings 46, 47, which are located closer to the inner side 35 of the cover 21 flush with this side thereof. In this way, the sealing rings 50, 51 are protected. In addition, the use of an elastic element with a different execution from the elastic element 33 allows to improve its fit in the area of the holes 46, 47 to the mating surfaces and in this way, first of all, to prevent the skewing of the elastic element 33. Such an elastic element 33 in an alternative embodiment, it is preferable to use primarily when the anchor rod 37 is supported on it. A similar embodiment is described, for example, below with reference to FIG.

In addition, figure 2 shows a possible connection of the body part 54 of the fuel injector 1 with the electromagnetic unit 2.

Figure 3 shows the electromagnetic assembly 2 of the electromagnetic valve 3 for the fuel injector 1 similar to that shown in figure 2 in accordance with a third embodiment of the invention. In this embodiment, an electrical connection 41 is provided for electrically connecting to the electrical contact part 49. In addition, an electrical connection 41 'is provided for electrically connecting to the electrical contact part 48. Due to this, the electrical wiring 42 can be connected to the electrical contact parts 48, 49.

In the considered embodiment, the elastic element 33 is made integral or continuous in its central part. Therefore, the sleeve 39 rests directly on the elastic element 33. The central part of the elastic element 33 also forms a stop to limit the stroke of the anchor rod 37. Thus, the elastic element 33, firstly, performs the function of motionlessly fixing the coil 30 by applying to it the forces of its preliminary compression . Secondly, the elastic element 33 performs the function of limiting the stroke of the anchor rod 37, and thereby the stroke of the armature 36.

FIG. 4 shows a sectional view of FIG. 3 of a cover 21 with an elastic member 33 of an electromagnetic assembly 2 for a solenoid valve 3 of a fuel injector 1 in accordance with a fourth embodiment of the invention. In this embodiment, the elastic element 33 is made in the form of a disk elastic element. The elastic element 33 further has an opening 38. Due to this, the anchor rod 37 (FIG. 1) can abut against the inner side 35 of the cover 21. In addition, the elastic element 33 is somewhat spaced apart from its inner part 35 from the inner side 35 of the cover 21 due to its disk-shaped execution. so that the drain hole 26 sloping through the cover 21 provides a connection of the inner space 23 with the drain channel 25 in the pipe 24 (Fig. 1). In this case, the pipe 24 can be connected to the cover 21 by welding in accordance with the second embodiment shown in FIG. 2.

The drain hole 26 has a countersink recess 60 in the area of the inner side 35 of the cover 21, through which the drain hole 26 enters the interior space 23 of the body part 20 (Fig. 1). The presence of such a countersink recess allows under certain conditions to improve the passage of fuel into the drain channel 25 in the nozzle 24. In addition, the presence of a countersink recess allows avoiding the need for the possibly required process of deburring along the edges of the drain hole 26 in the area of the inner side 35 of the lid 21, since the countersink recess 60 provides a fit of the elastic member 33 to the inner side 35 of the cover in a plane. The countersink to produce the countersink recess 60 allows, first of all, to remove the burrs formed during drilling, in which the elastic element 33 can abut under certain conditions. In addition, burrs that may remain after drilling are relatively close to the center of the inner side 35 of the lid, otherwise they can under certain conditions affect the stop of the anchor rod 37 in the cover. In this case, the countersink recess 60 ensures that the cover has an optimal contact surface for the anchor rod 37. As a result, the distortion of the anchor rod 37 leading to increased wear is prevented, thereby preventing the transverse forces from affecting the solenoid valve 3, thereby ensuring reliable operation of the fuel injector 1 In addition, the cover 21 can, after hardening, be subjected to mechanical grinding between two grinding wheels in order to further improve the fit of the anchor eraser to it reaping.

In this embodiment, a countersink recess 61 is also provided on the side of the cap 21 facing the nozzle 24. The presence of such a countersink recess eliminates the possible presence of burrs that may interfere with welding of the nozzle 24 to the cap 21.

FIG. 5 shows a fragment V of the electromagnetic assembly 2 of the fuel injector 1 in FIG. 3 in accordance with a fifth embodiment of the invention. In this embodiment, the elastic element 33 has a central bulge 62 facing the central hole 45 of the coil 30. Moreover, the elastic element 33 in its central part, i.e. in the zone of its central bulge 62, made solid or solid. Due to this, the central bulge 62 forms an abutment for the anchor rod 37. In addition, the sleeve 39, which serves as a guide for the anchor rod 37, rests on the central bulge 62 of the elastic element 33. In addition, the spring 40 rests on the central bulge 62 of the elastic element 33 through the sleeve 39 .

Considered by the example of the above-described embodiments of the invention, the possibilities for constructive implementation of the electromagnetic unit provide the possibility of its coordination with the design features of various systems. Moreover, the implementation of the electromagnetic unit with two or three welded joints first of all simplifies the coordination of the connector 28 on the pipe 24 with the required reciprocal connection. In addition, it is possible to efficiently assemble the electromagnetic assembly from the end 24 located on the side of the pipe. By taking simple structural measures, it is possible to protect the welds 22, 22 ', especially the weld 22' connecting the cover 21 to the pipe 24. For example, on the pipe 24, a circular or annular groove 63 may be provided (FIG. 2), which, in conjunction with the extrusion of the plastic lining, forms a barrier against water ingress. In addition, the electrical contact parts 48, 49 for the coil 30 can be brought out through simple holes in the cover 21 and sealed with O-rings 50, 51.

In addition, the force of its pre-compression applied by the elastic element 33 to the coil 30 can be adjusted during assembly, controlling the magnitude of such a force. In this way, it is possible to exclude mechanical overload of the magnetic material, deflection of the pole surfaces or the rise of the coil 30 from the step 32 of the body part 20 during operation due to too low or too high holding, respectively clamping forces, the value of which is determined by the pre-compression force of the elastic element. Of particular note is the possibility of adjusting the pre-compression force of the elastic element applied by it to the coil, with control depending on the movement. In this case, the cover 21 can be inserted into the body part 20 until it stops in it, which can be achieved, for example, by changing the position of the step 43 on the body part 20 or the position of the corresponding step 43 'on the cover 21. In this way, the parts are assembled in compliance with the specified size. In this case, the force developed by the elastic element 33 as a result of its preliminary compression is determined by the nominal dimensions of the individual parts, as well as their dimensional errors due to manufacturing tolerances.

To match the connector 28 with different requirements, it is also preferable to make a pipe 24 deep drawing. In addition, to create a preliminary pressing force, you can use a separate pre-compressible elastic element 33, which under certain conditions eliminates the use of a set or package of a Belleville spring and the corresponding disk.

The invention is not limited to the above options for its implementation.

Claims (16)

1. The electromagnetic assembly (2) of the electromagnetic valve (3) is primarily for the electromagnetic drive of the fuel injector, having a body part (20) with a coil (30) inserted in it, an armature (36), which is at least mainly located on the first side (31) coils (30), and a cover (21) covering the body part (20) from the second side (34) of the coil (30) facing away from the first side (31) and inseparably connected with the body part (20), characterized in that between the second side (34) of the coil (30) and the inner side (35) of the cover (21) is located a digested elastic element (33), which with the force of its preliminary compression loads the coil (30), which in this case, with its first side (31) rests on the ledge (32) of the body part (20). 2. The electromagnetic assembly according to claim 1, characterized in that the cover (21) is connected to the housing part (20) by at least one welded joint. 3. The electromagnetic assembly according to claim 2, characterized in that the welded joint forms a welded joint with a tight seam between the cover (21) and the body part (20). 4. The electromagnetic assembly according to claim 1, characterized in that an anchor rod (37) is connected to the anchor (36), which at least partially passes through the central hole (45) of the coil (30), and is provided on the elastic element (33) emphasis for the anchor rod (37), limiting its course when moving the armature (36) to the first side (31) of the coil (31). 5. The electromagnetic assembly according to claim 4, characterized in that the elastic element (33) has a central bulge (62) facing the central hole (45) of the coil (30) and forms a stop for the anchor rod (37). 6. The electromagnetic assembly according to claim 3, characterized in that the anchor rod (37) connected to the anchor (36) passes through the central hole (45) of the coil (30) facing the second side (34) of which the inner side (35) of the cover (21) while restricting the stroke of the anchor rod (37) when moving the armature (36) to the first side of the coil (31). 7. The electromagnetic node according to claim 6, characterized in that the elastic element (33) is made in the form of a plate-shaped elastic element, which has a Central hole (38). 8. The electromagnetic assembly according to claim 1, characterized in that the cover (21) has at least one hole (46, 47) through which at least one electrical contact part (48, 49) passes to the coil (30) and which is sealed by the sealing ring (50, 51) located therein. 9. The electromagnetic assembly according to claim 8, characterized in that a support ring (52, 53) is provided in said hole (46, 47), which is located closer to the inner side (35) of the cover (21) flush with this side thereof. 10. The electromagnetic assembly according to claim 1, characterized in that a pipe (24) is provided located on the outer side (44) of the cover (21), which has at least one drain hole (26, 27) connecting the closed cover (21 ) the inner space (23) of the body part (20), in which the coil (30) is located, with a drain channel (25) in the pipe (24). 11. The electromagnetic assembly of claim 10, wherein the drain hole (26, 27) in the lid (21) has a countersink recess (60) through which the drain hole (26) enters the interior (23) of the body part (20) ) 12. The electromagnetic assembly according to claim 10 or 11, characterized in that the pipe (24) is connected to the cover (21) by at least one welded joint (22 '). 13. The electromagnetic node according to claim 10 or 11, characterized in that the pipe (24) is made in one piece with the cover (21). 14. The electromagnetic assembly of claim 10, wherein the pipe (24) has at least one radially outer annular groove (63). 15. The electromagnetic assembly according to claim 14, characterized in that the cover (21) is made in the form of a disk-shaped cover (21). 16. The fuel nozzle (1) is primarily a fuel nozzle for diesel engine fuel systems having an electromagnetic drive (3) with an electromagnetic unit (2) according to one of claims 1 to 15 and a needle (5) driven by an electromagnetic drive (3) interacting with the contact surface (13) of its seat with the formation of a tight seat.

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